This epidemiologic study is designed to identify rsk factors for the several histologic types of ovarian cancer using case-control methodology. Exposures of specific interest are occupation, diet, medical and reproductive history, and drug use, particularly oral contraceptives and estrogens for menopause. Our goal is to identify risk factors that primarily may be modified to reduce disease ocurrence or that secondarily may be of clinical usefulness in defining the woman at risk for ovarian cancer, to achieve better control of the course of the disease.